Tow guide



United States Patent Charles H. McGill Decatur, Alabama 775,848

Nov. 14, 1968 Aug. 25, 1970 Monsanto Company St. Louis, Missouri a corporation of Delaware inventor Appl. No. Filed Patented Assignee TOW GUIDE 5 Claims, 5 Drawing Figs.

US. Cl 83/443, 83/403, 83/449 Int. Cl B65h 57/22 Field of Search 83/443, 448, 449, 438, 403; 226/196, 199; 57/(lnquired) [56] References Cited UNITED STATES PATENTS 2,424,555 7/1947 Curtis 83/403X 3,162,080 12/1964 Hemker 83/443X F ORElGN PATENTS 621,670 6/1961 Canada 83/403 Primary Examiner- Frank T. Yost Attorneys Robert L. Broad, .I r. and Roy P. Wymbs ABSTRACT: This invention concerns a tow guide having a pair of U-shaped guide members through which the tow passes to a cutter. The U-shaped guides are parallel to each other and are mounted for pivotal movement so that the pressure applied to the tow by the opposed facing surfaces of each of the guides can be adjusted.

Patented Aug. 25, 1970 HM l Q I. Q 1/ INVENTOR. CHARLES H. MC GILL Km ATTURNEY TOW GUIDE Cutters of the type disclosed in US. Pat. No. 1,723,998 to A. Beria are widely used in cutting continuous textile filaments into staple. One of the characteristics of this type cutter is that a twist is applied to the tow of filaments being fed into the cutter, this twist being a result of the high rotative speed of the cutter. When shorter lengths (i.e., l to 2 inches) are being cut the tow leading to the cutter is sufficient to prevent ballooning of the filaments in the tow. However, when the staple is being cut to greater lengths (i.e., to 6 inches) there is little twist imparted to the tow entering the cutter, since the tow is being fed into the cutter at a greater speed. This low amount of twist in the tow will allow filaments in the tow to balloon.

The low twist in the tow allows some sections (i.e., groups of filaments) of the tow to balloon. Then, when the balloon in the tow is drawn into the cutter and that section cut, the result is a group of staple fibers which are much longer than they should be. The ballooning effect will shift from one section in the tow to another so that a good many of the staple filaments in the final product will be longer than desired.

Further, the nature and characteristics of not only the filaments but also the steps used in producing the filaments can also have an affect on the ballooning and cutting characteristics of the filaments. It is a well known fact that the quality of synthetic filaments produced in a given plant may vary from day to day for no apparent reason. Logic will not usually provide an answer as to why filament quality is down. The usual procedure is to make minor adjustments in the production steps in an effort to raise quality to the desired level. The same thing applies to the cutting of the filaments into tow. The cutting procedure may proceed smoothly one day with little ballooning of the filaments in the tow and the next day, under what are apparently the same conditions, there may be a considerable amount of filament ballooning in the tow being cut. With these problems in mind one of the objects of this invention is to provide a novel and improved apparatus for guiding a tow into a cutting machine.

Another object of this invention is to provide an apparatus for guiding and distributing the twist in a tow of filaments fed to a rotary cutter.

Another object of this invention is to provide a tow guiding apparatus which is adjustable to compensate for variations in tow being fed to a cutter.

One embodiment of the invention contemplates a tow guide having a pair of U-shaped guide members, one of which is offset slightly from a linear path leading into a Beria cutter. The guide members are parallel to each other and are mounted for pivotal movement in such a manner that the pressure applied to opposite sides of the tow by opposite legs of each of the U- shaped guide members can be adjusted to distribute and control the twist in the tow.

Other objects of the invention will become apparent when the following detailed description is read in conjunction with the drawings, in which:

FIG. 1 is a perspective view showing the location of the apparatus of the present invention relative to the tow cutter;

FIG. 2 is an enlarged perspective view of the apparatus of the present invention with portions broken away to show the various elements of the apparatus;

FIG. 3 is a front view of a tow cutter with which this apparatus is used;

FIG. 4 is an enlarged fragmentary front view of the cutter ferrule showing the result of the ballooned filaments in the tow; and

FIG. 5 is a view of the apparatus of FIG. 4 illustrating the appearance of the end of the tow when no ballooning is present therein.

Referring now in detail to the drawing there is shown a frame in the form of a flat metal plate 11 supporting a pair of U-shaped guide members 12, the guide members 12 each having opposed guide surfaces adapted to engage opposite sides of a tow 17 moving therebetween. The tow 17 passes through the guides 12 one after the other and then enters a cutter 20 of the Beria type. The guide 12 nearest the cutter is positioned on the axis of rotation of the cutter 20 at the entrance thereof while the remote guide 12 is laterally spaced from this axis.

The frame 11 and its associated structure is positioned as shown between a feed roll 19 and the tow cutter 20, the cutter 20 being mounted in a housing 21. A detector 22 is used to detect knots and slack in the tow 17 being fed into the cutter. The feed roll 19, the detector 22 and the cutter 20 and its associated structure are conventional.

Secured to each of the guides 12 on the plate 11 is a short lever 24, the ends of the levers 24 being connected by a link 26. Movement of the link 26 will thus pivot the guides 12, the guides being secured to the shafts 27 which extend through the plate 11 and are secured to the levers 24. It will be noted that the guides 12 lie in parallel planes and pivot about parallel axes.

A handle 28 pivotally mounted on a pin 30 secured to the plate 11 is provided for moving the link 26 to pivot the guides 12. The link 26 is provided with a pin 31 which extends into a slot 32 in the handle 28 to connect the link 26 to the handle 28. The plate 11 is provided with an arcuate slot 34 through which extends a bolt 36 secured to the handle 28. A lock nut 37 threaded onto the bolt 36 is provided for locking the handle 28 to hold the guides 12 in the desired position.

In operation of the apparatus the operator utilizes a strobescopic light (not shown) to observe the end of the tow 17 exiting from the ferrule 38 of the cutter 20. If there is no ballooning of individual filaments in the tow the tow exiting from the ferrule 38 will have a crew cut appearance as best illustrated in FIG. 5. If some of the filaments in the tow are ballooning, the end of the tow will have the appearance illustrated in FIG. 4, with filaments 37 extending outward beyond the end of the tow 17. In the latter case the operator loosens the lock nut 37 and moves the handle 28 to pivot the guides 12 until the end of the tow regains the crew cut appearance illustrated in FIG. 5. Thus, a tedious determination of the cause of balloning of the filaments is obviated. 7

It is to be understood that the embodiment disclosed herein is merely illustrative and that numerous other embodiments can be contemplated without departing from the spirit and scope of the invention.

Iclaim:

1. An apparatus for guiding a tow of filaments into a rotary cutter, comprising:

a. a frame;

b. a pair of spaced guide members mounted on the frame,

each of said guide members having opposed guide surfaces for engaging opposite sides of a tow passed therebetween, said guide members being mounted for pivotal movement on the frame;

c. a link interconnecting the guide members; and

(1. means connected to the link for actuating said link to pivot the guide members.

2. The apparatus of claim 1 wherein one of the guide members is in alignment with the axis of rotation of the cutter and the other guide member is laterally spaced from said axis.

3. The apparatus of claim 1 wherein the guide members lie in parallel planes and are pivotable about parallel axes.

4. The apparatus of claim 3 wherein the guide members are U-shaped.

5. An apparatus for guiding a tow of filaments into a rotary cutter, comprising:

a. a plate positioned adjacent to the cutter;

b. a pair of spaced U-shaped guides extending from the plate, said guides lying in parallel planes and being mounted for pivotal movement about parallel axes;

c. a pair of levers secured to the guides;

d. a handle pivotally secured to the plate and having thereinv a slot;

e. a link interconnecting the levers, said link having a pin extending into the slot in the handle so that movement of the handle actuates the link to pivot the guides; and

f. means associated with the handle for locking said handle to the plate. 

